求极限LIM(趋近与0)(cot^2 *x-1/x^2)急
问题描述:
求极限LIM(趋近与0)(cot^2 *x-1/x^2)
急
答
求极限LIM(趋近与0)(cot^2 *x-1/x^2)
=LIM(趋近与0)(cos^2x/sin^2x-1/x^2)
=LIM(趋近与0)(cos^2x/x^2-1/x^2)
=LIM(趋近与0)(cos^2x-1)/x^2
=LIM(趋近与0)-sin^2x/x^2
=-1
求极限LIM(趋近与0)[(cot^2 *x-1)/x^2]吧